Duramax 6600
Updates and New
Features
Course #16340.50B
Caution
In order to reduce the chance of personal injury and/or property damage,
carefully observe the following informati...
Duramax 6600 Updates and New Features
i
Foreword
This manual contains diagnostic and service information regarding the Dur...
Table of Contents
ii
1. Introduction ......................................................1-1
Introduction .................
1. Introduction
1-1
Figure 1-2, The 2006 Duramax 6600
(full-size van application)
Figure 1-1, The Duramax 6600 for 2006
(E...
Notes
1-2
1. Introduction
2. Engine Mechanical Updates
2-1
Figure 2-1, 2006 Duramax 6600 Engine
Block
Figure 2-2, New Cylinder Heads and
Gaskets
Int...
2. Engine Mechanical Updates
2-2
Figure 2-3, New Cam (Scissor) Gear
Figure 2-4, Inside the Cam Gear is a
C-type Torsion Sp...
2. Engine Mechanical Updates
2-3
Figure 2-5, "Scissored" Cam Gear Teeth
Figure 2-6, Meshed Cam Gear Teeth
When the gear te...
2. Engine Mechanical Updates
2-4
Figure 2-7, A Lock Bolt through Gear
Halves Neutralizes Spring
Tension
Figure 2-8, EGR Co...
2. Engine Mechanical Updates
2-5
Figure 2-9, Air Intake Components for
Duramax-Equipped Express
Full-Size Vans
Figure 2-10...
2. Engine Mechanical Updates
2-6
Figure 2-12, IAH for Light-Duty Truck
(Left) and Full-Size Van
(Right) Applications
Figur...
2. Engine Mechanical Updates
2-7
Figure 2-14, Additional Intake Air
Temperature (IAT 2) Sensor
Figure 2-13, IAH Mega Fuse
...
2. Engine Mechanical Updates
2-8
Figure 2-16, Radiator & Fan Shroud
Figure 2-15, Water Pump
Cooling System
A larger volume...
2. Engine Mechanical Updates
2-9
Figure 2-18, Larger, Quick-Connecting
Lower Radiator Hose
Figure 2-17, Radiator Baffle
A ...
2. Engine Mechanical Updates
2-10
Figure 2-20, Auxiliary Transmission
Cooler and Lines
Figure 2-19, Charge Air Cooler Duct...
2. Engine Mechanical Updates
2-11
Figure 2-21, "Torca" Exhaust Clamp
Exhaust System
On light-duty truck applications, a "T...
Notes
2. Engine Mechanical Updates
2-12
3. 2006 Chevrolet Express and GMC Savana Update
3-1
Figure 3-1, Duramax 6600 Full-Size Van
Application
Figure 3-2, Revised...
3. 2006 Chevrolet Express and GMC Savana Update
3-2
Figure 3-3, Hydra-Matic 4L85-E
Figure 3-4, Full-Size Van Fuel Prime
Pu...
3. 2006 Chevrolet Express and GMC Savana Update
3-3
– IMPORTANT –
The fuel prime pump must be disabled before using the ex...
3. 2006 Chevrolet Express and GMC Savana Update
3-4
Figure 3-7, Access Panel for #5 Fuel
Injector (Seen From the
Passenger...
3. 2006 Chevrolet Express and GMC Savana Update
3-5
Figure 3-9, Fuel-Operated Coolant
Heater
Figure 3-10, Coolant Heater E...
3. 2006 Chevrolet Express and GMC Savana Update
3-6
The electronically controlled, coolant heater operates automatically, ...
4. Fuel System Update
4-1
Figure 4-1, Fuel Pump
Figure 4-2, Redesigned Fuel Injector
Revised Fuel Injection System
One of ...
4. Fuel System Update
4-2
Figure 4-5, Injection Flow Rate Value
Being Read
Figure 4-4, Fuel Injector Imprinted with
Inject...
4. Fuel System Update
4-3
Figure 4-6, Injection Flow Rate Values
Stored in the ECM and GPCM
During final vehicle assembly,...
4. Fuel System Update
4-4
Figure 4-8, Injector Flow Rate
Programming Data Display
Figure 4-7, Injector Flow Rate
Programmi...
4. Fuel System Update
4-5
Figure 4-10, Copy GPCM Injector Flow
Rate Values to ECM
Figure 4-11, Copy ECM Injector Flow Rate...
4. Fuel System Update
4-6
Fuel System Electrical Changes
As on the previous Duramax 6600, the ECM controls
the common fuel...
4. Fuel System Update
4-7
Figure 4-13, 2006 Duramax Fuel Injection Circuits
Notes
4. Fuel System Update
4-8
5. Electrical System and Engine Controls Update
5-1
Figure 5-1, Bosch E35 ECM
E35 Engine Control Module (ECM)
The control ...
5. Electrical System and Engine Controls Update
5-2
Figure 5-2, ECM Wiring Harness
5. Electrical System and Engine Controls Update
5-3
Figure 5-3, TCM and ECM
Figure 5-4, Glow Plug Control Module
With the ...
5. Electrical System and Engine Controls Update
5-4
Figure 5-6, Leak-Down Tester Adapter
J35667-8 and Compression
Gauge Ad...
5. Electrical System and Engine Controls Update
5-5
Figure 5-7, Glow Plug Control Circuit
5. Electrical System and Engine Controls Update
5-6
Figure 5-8, Manifold Absolute Pressure
(MAP) Sensor
Manifold Absolute ...
5. Electrical System and Engine Controls Update
5-7
Figure 5-10, Intake Air Temperature
(IAT 2) Sensor
Figure 5-9, EGR Sys...
5. Electrical System and Engine Controls Update
5-8
Figure 5-11, Intake Air Heater (Full-Size
Van Application)
Intake Air ...
Appendix
Appendix-1
2006 Duramax LLY Engine Controls and DTC Overview
Contents
A) MisfireMonitoring
B) Fuel System Monitor...
Appendix
Appendix-2
C. Thermostat Monitoring System (P0128)
Two thermostat valves are used to regulate the coolant flow ou...
Appendix
Appendix-3
E. Engine Controls Component DTC List
1. Fuel Injector Control Circuits
a. Fuel Injector Positive Volt...
Appendix
Appendix-4
Rationality Check
Crankshaft Position [CKP] Sensor Performance - P0336
Detects missing or extra crank ...
Appendix
Appendix-5
Turbocharger Over Boost - P0234
This diagnostic checks for an over boost condition when:
• The engine ...
Appendix
Appendix-6
7. Intake Air Temperature Sensor 2 (IAT2)
There is an additional intake air temperature sensor located...
Appendix
Appendix-7
9. Engine Coolant Temperature Sensor
The engine coolant temperature sensor is a thermistor type device...
Appendix
Appendix-8
11. Turbocharger Vane Control Position Sensor
The Turbocharger position sensor outputs a voltage corre...
Appendix
Appendix-9
14. Memory (ROM/RAM)
The ECM Read Only Memory stores the operational software and calibrations. The me...
Appendix
Appendix-10
18. Vehicle Speed Sensor
The vehicle output speed sensor contains a permanent magnet surrounded by a ...
GENERAL MOTORS
TRAINING MATERIALS
l Authentic GM Training Materials for
Classroom Courses, Videos, Certified-
Plus Trainin...
June 2005
General Motors Corporation
Course#16340.50B
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Duramax 6600 updates & new features booklet (english)

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Transcript of "Duramax 6600 updates & new features booklet (english)"

  1. 1. Duramax 6600 Updates and New Features Course #16340.50B
  2. 2. Caution In order to reduce the chance of personal injury and/or property damage, carefully observe the following information: The service manuals of General Motors Corporation are intended for use by professional, qualified technicians. Attempting service procedures without the appropriate training, tools, and equipment could cause personal injury, vehicle damage, or improper vehicle operation. Proper vehicle service is important to the safety of the service technician and to the safe, reliable operation of all motor vehicles. If a replacement part is needed, use the same part number or an equivalent part. Do not use a replacement part of lesser quality. The service manuals contain effective methods for performing service procedures. Some of the procedures require the use of tools that are designed for specific purposes. Accordingly, any person who intends to use a replacement part, a service procedure, or a tool that is not recommended by General Motors, must first establish that there is no jeopardy to personal safety or the safe operation of the vehicle. The service manuals contain Cautions and Notices that must be observed carefully in order to reduce the risk of injury. Improper service may cause vehicle damage or render the vehicle unsafe. The Cautions and Notices are not all-inclusive. General Motors cannot possibly warn of all the potentially hazardous consequences that may result by not following the proper service procedures. The service manuals cover service procedures for vehicles that are equipped with Supplemental Inflatable Restraints (SIR). Failure to observe all SIR Cautions and Notices could cause air bag deployment, personal injury, or otherwise unneeded SIR repairs. Refer to the SIR component and wiring location views in Restraints before performing a service on or around SIR components or wiring. If multiple vehicle systems are in need of repair, including SIR, repair the SIR system first to reduce the risk of accidental air bag deployment and personal injury.
  3. 3. Duramax 6600 Updates and New Features i Foreword This manual contains diagnostic and service information regarding the Duramax 6600 Diesel Engine (LLY); including features that make it unique, basic operation and service strategies, including tools required for service. Always refer to the applicable vehicle Service Information and appropriate Dealer Technical Service Bulletins for additional information regarding specific system operation and diagnostic/repair procedures. When this manual refers to a brand name, a number, or a specific tool, you may use an equivalent product in place of the recommended item, unless instructed otherwise. All information, illustrations, and specifications in this manual are based on the latest product information available at the time of publication approval. General Motors reserves the right to make changes at any time without notice. When technical assistance is required, call the Technical Assistance Center at 1-877-446-8227. Published by General Motors Corporation, Service Operations, Warren, Michigan 48090-9008. © 2005 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED. LITHO IN U.S.A. No part of this book may be reproduced, stored in any retrieval system, or transmitted in any form or by any means (including but not limited to electronic, mechanical, photocopying, and recording) without prior written permission of General Motors Corporation. This applies to all text, illustrations, tables and charts. All product names throughout this book are trademarks or registered trademarks of their respective holders.
  4. 4. Table of Contents ii 1. Introduction ......................................................1-1 Introduction ......................................................1-1 2. Engine Mechanical Updates...........................2-1 InternalEngineUpdates ...................................2-1 Block ................................................................2-1 Pistons .............................................................2-1 Cylinder Heads and Gaskets ............................2-1 Connecting Rod Bushings and Journal Bearings ............................................2-1 Scissor Type Cam Gear ...................................2-2 ExternalEngineUpdates ..................................2-4 TurboVanes.....................................................2-4 EGRCooler ......................................................2-4 Air Induction System ........................................2-5 Intake Air Heater ..............................................2-6 Intake Air Temperature Sensor 2 (IAT 2) ..........2-7 Cooling System ................................................2-8 Exhaust System ............................................2-11 3. 2006 Express and Savana Full-size Van........3-1 2006 Chevrolet Express and GMC Savana Update ..............................................3-1 Full-Size Van Introduction ................................3-1 Express and Savana Electric Fuel Prime Pump ...................................................3-2 Transmission....................................................3-2 Prime Pump Service Tools...............................3-3 Fuel Injector Access ........................................3-4 Express and Savana Fuel Operated Coolant Heater ...............................................3-5 CoolantHeaterOperation .................................3-6 Coolant Heater Scan Tool Access ...................3-6 4. Fuel System Updates ......................................4-1 Revised Fuel Injection System ..................4-1 Injection Flow Rate Programming ..............4-2 Fuel Injector Flow Rate ProgrammingServiceScenarios................4-3 Injector Flow Rate Programming Procedures ..............................................4-4 Fuel System Electrical Changes................4-6 5. Electrical System and Engine ControlsUpdate ...............................................5-1 E35 Engine Control Module (ECM) ...................5-1 Glow Plug Control Module ................................5-4 Special Tools ...................................................5-4 Manifold Absolute Pressure (MAP) Sensor and BARO Sensor..............................5-6 Intake Air Temperature (IAT 2) Sensor .............5-7 Exhaust Gas Recirculation (EGR) System .......5-7 Intake Air Heater ..............................................5-8 Appendix: 2006 Duramax LLY Engine Controls and DTC Overview ....................................................... A1 Contents .......................................................... A-1 A. Misfire Monitoring System ......................... A-1 B. Fuel Monitoring System............................. A-1 C. Thermostat Monitoring System (P0128) ................................................... A-2 D. Exhaust Gas Recirculation (EGR) System Monitoring ................................. A-2 E. Engine Controls Component DTC List ...... A-3 1. Fuel Injector Control Circuits .............. A-3 2. Crankshaft Angle Sensor .................... A-3 3. Camshaft Angle Sensor...................... A-4 4. Manifold Absolute Pressure Sensor ... A-4 5. Barometric Pressure Sensor .............. A-5 6. Intake Air Temperature Sensor........... A-5 7. IntakeAirTemperature Sensor 2 (IAT2) ................................ A-6 8. FuelTemperatureSensor ................... A-6 9. EngineCoolantTemperatureSensor .. A-7 10. Mass Air Flow Sensor ........................ A-7 11. TurbochargerBoostControl Position Sensor ............................... A-8 12. TurbochargerBoostControlSolenoid Circuit ............................................. A-8 13. Glow Plug Control Module and Glow Plugs ............................... A-8 14. Memory(ROM/RAM) .......................... A-9 15. Malfunction Indicator (MIL) Lamp ....... A-9 16. Wait To Start (WTS) Lamp ................. A-9 17. ECM - TCM Communications ............. A-9 18. Vehicle Speed Sensor ...................... A-10
  5. 5. 1. Introduction 1-1 Figure 1-2, The 2006 Duramax 6600 (full-size van application) Figure 1-1, The Duramax 6600 for 2006 (Express/Savana version) Introduction This course describes the technological enhancements that the Duramax 6600 engine received for the 2006 model year. The 6.6 liter diesel Duramax engine has been continuously refined each year since its introduction in 2001. It received extensive modifications with the introduction of RPO LLY VIN Code 2. The benefits included increased torque output and lower exhaust emissions. The latest updates, covered in this course, are aimed at further refining the engine's operation while continuing to enhance durability. The Duramax engine also becomes more widely available in 2006 when it is offered as an optional powerplant for Chevy Express and GMC Savana Full- Size Vans (Fig. 1-2). The engine will remain as an option for all current applications.
  6. 6. Notes 1-2 1. Introduction
  7. 7. 2. Engine Mechanical Updates 2-1 Figure 2-1, 2006 Duramax 6600 Engine Block Figure 2-2, New Cylinder Heads and Gaskets Internal Engine Updates Block Cylinder block casting and machining processes are changed to provide the cast iron block (Fig. 2-1) with more bulkhead reinforcement for increased reliability anddurability. Pistons The pistons are revised with a new design that helps lower the engine's compression ratio from 17.7 to 1 to 16.8 to 1. Cylinder Heads and Gaskets New cylinder heads and head gaskets (Fig. 2-2) are used to accommodate the lowered compression and increased firing pressure. The lowered compression ratio serves to reduce engine noise at idle and improve overall smoothness. Connecting Rod Bushings and Journal Bearings The connecting rod bushings and journal bearings are also revised for increased durability.
  8. 8. 2. Engine Mechanical Updates 2-2 Figure 2-3, New Cam (Scissor) Gear Figure 2-4, Inside the Cam Gear is a C-type Torsion Spring Scissor Type Cam Gear One of the most significant mechanical modifications to the 2006 Duramax is a new camshaft gear (Fig. 2-3). The gear is a spring-loaded design, usually referred to as a "scissor" gear. It consists of two gear halves sandwiched over a C-type torsion spring (Fig. 2-4).
  9. 9. 2. Engine Mechanical Updates 2-3 Figure 2-5, "Scissored" Cam Gear Teeth Figure 2-6, Meshed Cam Gear Teeth When the gear teeth are in mesh with another gear, the spring forces the two gear halves to move (Fig. 2-5), relative to one another, until the tooth space on the mating gear is filled. This scissor action of the gear halves is what gives the gear its name. The chief advantage of this type of gear is that the spring action keeps the drive gear and driven gears in constant mesh (Fig. 2-6). This eliminates backlash and helps reduce gear noise. Also, the spring loading automatically adjusts gear contact to compensate for wear or thermal dimensional changes.
  10. 10. 2. Engine Mechanical Updates 2-4 Figure 2-7, A Lock Bolt through Gear Halves Neutralizes Spring Tension Figure 2-8, EGR Cooler Before removing the cam gear for service, you must insert a lock bolt through the gear halves to neutralize the spring tension (Fig. 2-7). With the lock bolt installed, you can safely remove the bolt retaining the cam gear to the shaft. Never loosen the cam gear retaining bolt without first inserting the lock bolt. External Engine Updates Turbo Vanes The vanes in the variable-geometry impeller system are modified so that the turbocharger is more aerodynamically efficient. This change enhances the turbocharger's ability to deliver smooth and immediate response while further reducing emissions. EGR Cooler The EGR cooler (Fig. 2-8) that was introduced on the 2004 LLY engine is enlarged to provide increased exhaust gas cooling capacity.
  11. 11. 2. Engine Mechanical Updates 2-5 Figure 2-9, Air Intake Components for Duramax-Equipped Express Full-Size Vans Figure 2-10, Revised Air Intake Components for Duramax- Equipped Light-Duty Trucks Air Induction System There are a number of modifications in the engine cooling and air induction systems for 2006 models. A new fan is used and the fan clutch is also a new design. The engine-mounted fan shroud and mounting brackets are also new. The entire air induction system is retuned for more efficient, quieter operation. New induction components include the air filter, air box and the duct between the filter box and the turbocharger inlet (Figs. 2-9, 2-10).
  12. 12. 2. Engine Mechanical Updates 2-6 Figure 2-12, IAH for Light-Duty Truck (Left) and Full-Size Van (Right) Applications Figure 2-11, Intake Air Heater (IAH) Intake Air Heater A new intake air heater (IAH) is also used on the 2006 LLY (Fig. 2-11). Heating the intake air helps to reduce smoke and emissions during cold or light-load driving. The IAH features a grid heater (Fig. 2-12), which is triggered automatically by the ECM to reduce white smoke during cold weather operation.
  13. 13. 2. Engine Mechanical Updates 2-7 Figure 2-14, Additional Intake Air Temperature (IAT 2) Sensor Figure 2-13, IAH Mega Fuse Intake Air Temperature Sensor 2 (IAT 2) There is an additional intake air temperature sensor (Fig. 2-14), located on the right side of the intake manifold. The second sensor provides the ECM with temperature of the actual combustion air as it enters the cylinders. The ECM uses this data in its timing and fuel adjustment calculations to help reduce emissions. A secondary function for the second IAT 2 sensor is control of the EV fan. Power for the IAH is provided through an added 175 amp mega fuse (Fig. 2-13).
  14. 14. 2. Engine Mechanical Updates 2-8 Figure 2-16, Radiator & Fan Shroud Figure 2-15, Water Pump Cooling System A larger volume water pump (Fig. 2-15) is used on the 2006Duramax. A larger radiator is used and the upper and lower radiator shrouds and support are redesigned. Mounting the fan shroud directly to the engine provides increased cooling ability.
  15. 15. 2. Engine Mechanical Updates 2-9 Figure 2-18, Larger, Quick-Connecting Lower Radiator Hose Figure 2-17, Radiator Baffle A new radiator baffle (Fig. 2-17) is common to both Chevrolet and GMC applications. The lower radiator hose is also larger for increased coolant flow (Fig. 2-18). A new quick-connect attachment connects the hose to the radiator.
  16. 16. 2. Engine Mechanical Updates 2-10 Figure 2-20, Auxiliary Transmission Cooler and Lines Figure 2-19, Charge Air Cooler Duct with Quick-Connects An updated auxiliary transmission fluid cooler (Fig. 2-20) has been added. The oil cooler lines are also new. Quick connects are also used on the new cold-side Charge Air Cooler duct (Fig. 2-19). Because of the change in the duct between the charge air cooler and intake air heater, a new tool, J46091-5, Charge Air Cooler Tester Adapter (not shown) is required for light-duty truck applications.
  17. 17. 2. Engine Mechanical Updates 2-11 Figure 2-21, "Torca" Exhaust Clamp Exhaust System On light-duty truck applications, a "Torca" style band clamp (Fig. 2-21) is now used between the exhaust downpipe and the rear muffler.
  18. 18. Notes 2. Engine Mechanical Updates 2-12
  19. 19. 3. 2006 Chevrolet Express and GMC Savana Update 3-1 Figure 3-1, Duramax 6600 Full-Size Van Application Figure 3-2, Revised Instrument Panel 2006 Chevrolet Express and GMC Savana Update Full-Size Van Introduction For the 2006 model year, the 6.6L Duramax 6600 turbodiesel V-8 will be available in the Chevrolet Express and GMC Savana full-size G-vans (Fig. 3-1). To support the new powertrain, Express and Savana models equipped with the Duramax 6600 also include: • Revised front floor panel and underbodyheatshielding • New interior engine cover • High idle switch added to instrument panel(optional) • Instrument cluster revised to reflect diesel engine functionality (Fig. 3-2) • Standard145-ampalternator • Primary battery located underhood, with secondary battery mounted on left-hand frame rail • Ambulance package equipped with a 50-amp Maxi fuse connector at the B-pillar
  20. 20. 3. 2006 Chevrolet Express and GMC Savana Update 3-2 Figure 3-3, Hydra-Matic 4L85-E Figure 3-4, Full-Size Van Fuel Prime Pump (Left) Transmission When the Duramax is used in full-size van applications, it is teamed with the Hydra-Matic 4L85-E heavy-duty transmission (Fig. 3-3). Express and Savana Electric Fuel Prime Pump Some additional components are used for the Duramax engines used in the full-size Chevy Express and GMC Savana van. An electric fuel prime pump (Fig. 3-4), mounted on the frame rail of the van, replaces the hand pump in all Duramax-equipped full-size vans. A fuel filter is located beside the pump. There is also a removable filter located on the prime pump. The recommended service interval in the Duramax owner's guide Maintenance II schedule should be followed as a guide for replacing both of these filters.
  21. 21. 3. 2006 Chevrolet Express and GMC Savana Update 3-3 – IMPORTANT – The fuel prime pump must be disabled before using the existing vacuum gauge to diagnose the fuel system. The pressure with the pump running can reach 276 kPa (40 psi), much more than the 69 kPa (10 psi) the gauge is designed to handle. Figure 3-5, EN47620 - Fuel Pressure Gauge Adapter Figure 3-6, EN47969 - Fuel Supply Diagnostic Hose Prime Pump Service Tools There are two special service tools associated with the prime pump. These are a Fuel Pressure Gauge Adapter, tool number EN47620 (Fig. 3-5) for use with the existing fuel pressure gauge J 34730-1A to diagnose prime pump concerns. The fuel pressure kit is J 34370 There is also a clear fuel supply diagnostic hose EN47969 (Fig. 3-6) that can also be used for fuel system diagnosis on all LLY applications.
  22. 22. 3. 2006 Chevrolet Express and GMC Savana Update 3-4 Figure 3-7, Access Panel for #5 Fuel Injector (Seen From the Passenger Compartment) Figure 3-8, Access Panel Removed Fuel Injector Access Because of the positioning of the Duramax engine in the full-size Chevrolet and GMC Vans, a removable body panel (Fig. 3-7) is provided to allow access to the number 5 fuel injector (Fig. 3-8).
  23. 23. 3. 2006 Chevrolet Express and GMC Savana Update 3-5 Figure 3-9, Fuel-Operated Coolant Heater Figure 3-10, Coolant Heater Exhaust The fully integrated Fuel Operated Heater system is designed into the Express and Savana chassis, saving owners the time and labor of upfitting an aftermarket system; an industry-first for full-size vans. Similar style heaters are often used on recreational and other commercial vehicles. The unit features a self-contained, pressurized coolant heater, that uses diesel fuel to generate up to 17,200 Btu/h (5 kw) of heating energy. The coolant heater is equipped with an exhaust system (Fig.3-10). Express and Savana Fuel Operated Coolant Heater A unique option available for Duramax-equipped 2006 Full-Size Vans is a factory-installed, fuel-operated heater (Fig. 3-9) that provides auxiliary engine coolant heating in cold weather. In Service Information, the unit is referred to as the coolant heater, RPO code K08.
  24. 24. 3. 2006 Chevrolet Express and GMC Savana Update 3-6 The electronically controlled, coolant heater operates automatically, turning on and off within set parameters. The heater only runs when the engine is already running and its operation is fully integrated with the vehicle's coolant and fuel systems. Coolant Heater Operation The Coolant Heater turns ON when: • Outside air temperature <= 39° F (4° C) • Engine is running • Fuel level > 12.5% total volume of fuel tank • Coolant temp <= 167° F (75° C) The Coolant Heater turns OFF when: • Outside air temperature > 39° F (4° C) • Engine is not running • Fuel level < 12.5% total volume of fuel tank • Coolant temp >= 185° F (85° C) Coolant Heater Scan Tool Access Operation of the heater can also be monitored with the scan tool. The scan tool navigation path for accessing coolant heater data is as follows: – Diagnostics – 2006 – LD Trk, MPV, Incomplete – Chevrolet Truck/GMC Truck – G – Express/Savana – Powertrain – 6.6 L V8 LLY Diesel F0: Diagnostic Trouble Codes (DTC) F1: Data Display F2: Auxiliary Heater Data Display F2: Special Functions F3: Auxiliary Heater Output Controls F3: Snapshot F4: I/M System Information F5: Calibration ID – AuxiliaryHeaterModule – SoftwarePartNumber – ModelNumber
  25. 25. 4. Fuel System Update 4-1 Figure 4-1, Fuel Pump Figure 4-2, Redesigned Fuel Injector Revised Fuel Injection System One of the major enhancements for the latest Duramax 6600 is the revised fuel injection system. A new fuel pump design (Fig. 4-1) increases fuel pressure in the common-rail system from 23,200 psi (160 MPa) to 26,000 psi (180 MPa). An important point to note on the 2006 engine is that, if the monitored fuel pressure rises above the maximum, the pressure relief valve opens and remains open until the engine is shut OFF. When the valve opens, the pressure drop in the rail will cause DTC P0087: Fuel Rail Pressure (FRP) too low to set. The fuel injectors (Fig. 4-2) themselves are also new and feature a 7-hole spray nozzle that helps to more finely atomize the fuel spray in the cylinder. The injectors are positioned in the head so that they spray directly on the glow plugs to aid fast start-up in cold conditions (Fig. 4-3). Figure 4-3, Injector Spray Pattern
  26. 26. 4. Fuel System Update 4-2 Figure 4-5, Injection Flow Rate Value Being Read Figure 4-4, Fuel Injector Imprinted with Injection Flow Rate Programming Value Injection Flow Rate Programming During the fuel injector manufacturing process, each injector is tested and its flow rate is measured at several points. These measurements are recorded as the Injection Flow Rate value. This data is then recorded on a bar code label and laser etched as a hex number on the body of the injector (Fig. 4-4) before it is shipped to the Duramax engine assembly plant. As the injectors are installed on the engine in the Duramax manufacturing plant, the bar code is read (Fig. 4-5) on each injector and then stored in the DMAX computer system, along with the cylinder location in which the injector is installed. This information is also transmitted to a factory Fuel Bleed Machine that writes the information to the Glow PlugControlModule. – NOTE – Due to changes made after the completion of the video, some of the terminology used in the following Injection Flow Rate Programming sections varies from the video. This booklet contains the most current terminology.
  27. 27. 4. Fuel System Update 4-3 Figure 4-6, Injection Flow Rate Values Stored in the ECM and GPCM During final vehicle assembly, the value and cylinder position information from the GPCM is copied and written to the ECM memory when it is installed in the truck and the EE PROM is flashed. The vehicle leaves the assembly plant with two identical copies of stored values, one in the GPCM and one in the ECM (Fig. 4-6). During engine operation, the ECM uses Injection Quantity Adjustment (IQA) calibrations, based on the injection flow rate values, to more precisely adjust the fuel injection quantity for each cylinder. This contributes to combustion efficiency and reduced emissions. When the ignition is turned on, both the glow plug control module and the ECM check that injection flow rate values for all injectors are flashed in memory. If any value is missing, the Glow Plug Control Module sets code P160C signifying that injection flow rate values are not programmed in its memory. Similarly the ECM will set code P268A to signal that the injection flow rate values are not programmed. Fuel Injector Flow Rate Programming Service Scenarios There are a number of fuel system service situations where injector and module programming will directly affect service procedures and related service information. Situations include: • Injectorreplacement • ECM service or replacement • Glow Plug Control Module service or replacement. Performing any of these procedures could result in a condition where the injection flow rate values stored in the modules does not match the injector. Injectors beingswappedduringdiagnosis(NOTrecommended) could also produce the same result. For example, while diagnosing an engine performance concern, a technician swaps injectors between cylinders. He observes no difference in engine performance and continues with the repair. After completing repairs, he forgets to return the injectors to their original cylinder positions. The engine may run properly but the values in the ECM and GPCM will be different. This could lead to confusion the next time the vehicle is serviced, or if another symptom occurs. The important point to remember is that the relationship of the injector flow values in the ECM, the Glow plug control module and the injectors must be maintained in order for the fuel delivery system to function as it is designed. Do not swap parts from other vehicles when performing fuel system diagnosis and repairs. Use only service replacement parts for your repairs and the service programming procedures will ensure that the correct injection flow rate value relationships are maintained for the vehicle.
  28. 28. 4. Fuel System Update 4-4 Figure 4-8, Injector Flow Rate Programming Data Display Figure 4-7, Injector Flow Rate Programming Menu Figure 4-9, Reprogramming Injector Flow Rate Values for a New Injector Selecting F0: Display ECM and GPCM Inj. Flow Rates, allows for the viewing of the current injector flow rate values stored in both the ECM and GPCM for each injector (Fig. 4-8). Selecting F1: Reprogram Injector Flow Rates, allows for the reprogramming of individual injector flow rate values into both the ECM and GPCM after an injector is replaced (Fig. 4-9). Injector Flow Rate Programming Procedures The tech 2 is used to program individual injectors, the ECM and the GPCM. The Tech 2 programming path is as follows: – Build the vehicle – Select"Powertrain" F2: Special Functions F2: Fuel System F4: Injector Flow Rate Programming This will lead to the Injector Flow Rate Programming menu (Fig. 4-7).
  29. 29. 4. Fuel System Update 4-5 Figure 4-10, Copy GPCM Injector Flow Rate Values to ECM Figure 4-11, Copy ECM Injector Flow Rate Values to GPCM Selecting F3: Copy ECM Inj. Flow Rates to GPCM, allows for the copying of the flow rate values for all eight injectors from the ECM to the GPCM when a new GPCM is installed (Fig. 4-11). Selecting F2: Copy GPCM Inj. Flow Rates to ECM, allows for the copying of the flow rate values for all eight injectors from the GPCM to the ECM when a new ECM is installed (Fig. 4-10).
  30. 30. 4. Fuel System Update 4-6 Fuel System Electrical Changes As on the previous Duramax 6600, the ECM controls the common fuel rail pressure using the fuel rail pressure regulator on the fuel injection pump and monitors voltage feedback from the fuel rail pressure sensor. For 2006, the pressure sensor is relocated to end of the right side fuel rail (Fig. 4-12). An added DTC, P0191, now sets when the ECM detects that FRP sensor voltage is out of range compared to the atmospheric pressure. Fuel Injection diagnostic circuits have also been modified. As before, there are high and low side fuel injector control circuits. The DTC numbers P0201 through P0208 for the eight injector control circuits remain unchanged. On the 2005 Duramax LLY, voltage control circuits are divided into two groups of 4 cylinders each. On the new LLY there are four groups of cylinder voltage circuits. So there are 2 cylinders on each group (Fig. 4-13). Injector driver chips have internal diagnostics that detect electrical faults, such as opens, shorts to voltage and shorts to ground. When an error is detected, a 32 bit message enables the ECM to determine the injector number, injector driver group number and the injector driver chip number. If only the individual injector code, P0201 through 8 sets, only the affected injector is shut off. If a DTC is set for the injector driver group, both injectors in the affected group are turned OFF. Figure 4-12, Fuel Rail Pressure Sensor
  31. 31. 4. Fuel System Update 4-7 Figure 4-13, 2006 Duramax Fuel Injection Circuits
  32. 32. Notes 4. Fuel System Update 4-8
  33. 33. 5. Electrical System and Engine Controls Update 5-1 Figure 5-1, Bosch E35 ECM E35 Engine Control Module (ECM) The control functions for the fuel injection system are now integrated in the vehicle's Engine Control Module or ECM. The 2006 Bosch-manufactured ECM (Fig. 5-1) incorporates the first application of a more powerful E35 controller. This 32-bit processor can support up to five injection pulses per combustion event. Because of the added processing power this Bosch E35 controller provides, the separate Fuel Injection Control Module or "FICM" that was used in previous model years is not required. The injector circuit cooling function that was previously a function of the FICM is also not needed because the new injector system operating voltage is less than half that of the previous system and circuit heating is not an issue. During the manufacturing processes, the flow quantity of each injector is measured and this data, together with the injector's cylinder position, is stored in the memory of both the Glow Plug Control Module and the ECM. The 32-bit ECM can use injector flow data to precisely meter fuel delivery to individual cylinders and compensate for flow variations among individual injectors. Some of you may be familiar with the similar QR injector ID codes that are used on the Duramax 7.8 liter, LG4 engine. When an injector is newly installed in a vehicle, it is necessary to update the ID codes in the ECM.
  34. 34. 5. Electrical System and Engine Controls Update 5-2 Figure 5-2, ECM Wiring Harness
  35. 35. 5. Electrical System and Engine Controls Update 5-3 Figure 5-3, TCM and ECM Figure 5-4, Glow Plug Control Module With the new Bosch ECM and the Transmission Control Module, the wiring harness connection is modified. The ECM now uses two cam-lock connectors instead of three. The wiring harness itself is modified to provide a direct connection between the ECM and battery positive (Fig. 5-2). Engine Control Module DTC Update The 2006 Duramax LLY ECM, TCM and GPCM (Figs. 5-3, 5-4) communicate over the GM Local Area Network or GMLAN. All other modules continue communicate with the ECM via class 2. If the ECM does not receive messages from the Glow Plug Control Module on the GMLAN, DTC U0106 is set. There are a number of new DTC's for the ECM itself. The following codes set when the ECM detects errors in its internal processors and functions: P060B - Control Module Analog to Digital Performance P061C - Control Module Engine Speed Performance P062C - Control Module Vehicle Speed Performance P062F - Control Module Long Term memory Performance Revised Glow Plug Control Module and GPCM DTC Update
  36. 36. 5. Electrical System and Engine Controls Update 5-4 Figure 5-6, Leak-Down Tester Adapter J35667-8 and Compression Gauge Adapter EN47603 Figure 5-5, Glow Plug Control Module (Full-Size Van Application) Special Tools Incidentally, because the new glow plugs have different thread locations than the previous models, new adapters are required for cylinder test tools that use the glowplugopening. The new cylinder head leak-down tester adapter is J35667-8 and the new compression gauge adapter is EN47603 (Fig. 5-6). The actual test procedures are unchanged. Glow Plug Control Module The Glow Plug Control Module (Fig. 5-5) is a new design, as are the glow plugs themselves. The Glow Plug Control Module uses the same DTCs for the individual glow plugs as the previous model. DTC's P0671 through 0678 identify the status of each glow plug circuit (Fig. 5-7). A new code P064C, Glow Plug Control Module Performance sets if an error is detected within the controlmodule.
  37. 37. 5. Electrical System and Engine Controls Update 5-5 Figure 5-7, Glow Plug Control Circuit
  38. 38. 5. Electrical System and Engine Controls Update 5-6 Figure 5-8, Manifold Absolute Pressure (MAP) Sensor Manifold Absolute Pressure (MAP) Sensor and BARO Sensor New for 2006 is the addition of a Manifold Absolute Pressure, or MAP, sensor (Fig. 5-8). The MAP sensor responds to pressure changes in the intake manifold that vary with engine speed and load. The MAP sensor performs the functions that were performed by the turbo boost sensor on the 2005 Duramax. The sensor was renamed to conform to Federally-mandatedindustrystandards. Also on the 2006 Duramax, the BARO sensor is incorporated into the ECM. The ECM uses the BARO voltage signal to calibrate the fuel injection quantity and injection timing for altitude compensation. The ECM can detect a biased sensor by comparing the BARO and MAP signals at key ON and idle when both sensors are exposed to atmospheric pressure and should be the same. DTC P0106 is set if the ECM detects that the signals from the MAP sensor BARO sensor do not correlate. Additional DTCs are included for when the ECM detects MAP Sensor Circuit voltage is lower or higher than the calibrated voltage. Manifold Absolute Pressure (MAP) Sensor Circuit Low/ High Voltage - P0107/P0108. The ECM uses MAP sensor data to determine when turbo charger over or under boost conditions are present. The DTCs remain the same as before although the calculations have changed. The ECM checks the turbocharger vane position sensor readings while the vanes are being commanded. DTC P2563 sets if the actual vane position varies from the commanded position by more than 15 percent. A new DTC, P003A, replaces P0046 and sets if the position sensor shows that signals from the vanes are outside a calibrated specification.
  39. 39. 5. Electrical System and Engine Controls Update 5-7 Figure 5-10, Intake Air Temperature (IAT 2) Sensor Figure 5-9, EGR System Intake Air Temperature (IAT 2) Sensor A second Intake Air Temperature sensor (Fig. 5-10), located in the center intake manifold, is used in conjunction with the added intake air heater. The second sensor is identified as IAT 2 and functions identically to Sensor 1. DTCs for the IAT Sensor 2 Low and High voltage are P0097 and P0098 respectively. Exhaust Gas Recirculation (EGR) System There are also some new DTCs for the EGR system. P0402 now sets when the ECM detects that EGR flow is excessive. This compliments the existing code P0401 for insufficient flow. There is also an updated code, P046C, EGR Position Sensor Performance, for when the desired EGR valve position does not match the actual position, indicating the valve may be stuck.
  40. 40. 5. Electrical System and Engine Controls Update 5-8 Figure 5-11, Intake Air Heater (Full-Size Van Application) Intake Air Heater The GPCM uses the Intake Air Heater (Fig. 5-11) feedback to monitor multiple circuits for a number of conditions. P0540 Sets If: • No current detected through heater grid. • Low current detected through heater grid. • IAH Overtemp. • IAH Over or under voltage. • Groundopen. • IAH Switch defective. • Temperature line open or shorted. • IAH Resistance too high. Refer to the most current Service Information for specific details and service procedures for the new fuel system and engine controls data.
  41. 41. Appendix Appendix-1 2006 Duramax LLY Engine Controls and DTC Overview Contents A) MisfireMonitoring B) Fuel System Monitoring C) ThermostatMonitoring D) Exhaust Gas Recirculation (EGR) System Monitoring E) ComprehensiveComponentList A. Misfire Monitoring System Misfire monitoring is a function of the variation in crankshaft rotating speed, which is a function of the variation in torque resulting in a misfire. The minimum average cylinder speed is sensed on the basis of signals from the crankshaft angle sensor. This minimum speed is calculated every 2 engine revolutions. In addition, the camshaft angle sensor signals are also used to monitor cylinders position to determine in which cylinder the misfire occurred. As soon as the actual cylinder speed falls below the minimum average cylinder speed, a misfire is sensed and a misfire counter is updated. Misfire monitoring operates as on previous versions of the Duramax. Injector balance rates are a factor in determining misfires. For more information on misfire monitoring, see DTC codes P0300 - P0308 in Service Information. B. Fuel Monitoring System A target rail pressure is determined to obtain desired performance and emissions. The target fuel pressure in the common rail is maintained by modulating the duty cycle of the rail pressure control valve. The fuel pressure control valve is controlled by a Low Side Driver on the ECM. The fuel rail pressure sensor provides the feedback used in this control. The following monitors diagnose this system: Fuel Rail Pressure [FRP] Too Low - P0087 Detects a rail pressure below a minimum threshold OR a rail pressure delta below the target pressure. Fuel Rail Pressure [FRP] Too High - P0088 Detects a rail pressure above a maximum threshold OR a rail pressure delta above the target pressure. Fuel Pressure Regulator Control Circuit - P0090 Detects opens and shorts checks on the Fuel Pressure Regulator Control Circuit using the ECM electronic output driver circuitry fault detection. Fuel Rail Pressure [FRP] Sensor Performance - P0191 Detects in range sensor faults by comparing the sensor voltage when the common rail is not being pressurized to a voltage range corresponding to atmospheric pressures. Fuel Rail Pressure [FRP] Sensor Circuit Low Voltage - P0192 Detects circuit shorts to ground causing a low voltage condition on the sensor input. Fuel Rail Pressure [FRP] Sensor Circuit High Voltage - P0193 Detects circuit opens or short to battery causing a high voltage condition on the sensor input.
  42. 42. Appendix Appendix-2 C. Thermostat Monitoring System (P0128) Two thermostat valves are used to regulate the coolant flow out of the engine and into the radiator. These temperature activated valves open when the coolant they are exposed to reaches a certain temperature. 82°C for one thermostat; 85°C for the second. Restricting the flow of coolant out of the engine maintains a desired engine operating temperature. The diagnostic detects if the measured coolant temperature fails to reach one of the following: • 50°C when the Estimated Ambient Air Temperature < 10°C or • 72°C when the Estimated Ambient Air Temperature > 10°C. The performance of the thermostat is checked against a coolant temperature model. The model calculates the rise in coolant temperature based on factors like fuel consumption and intake air temperature. After the engine starts running, the model will initialize to the actual coolant temperature. Then as the engine consumes fuel, the model updates the expected coolant temp. As a result, the diagnostic will fail when one of the following conditions is true: • Model coolant temperature > 55°C and actual coolant temp < 50°C or • Model coolant temperature > 80°C and actual coolant temp < 72°C. This is a model based approach which compensates for elevated start-up coolant and ambient air temps varying within a the temperature regions. D. Exhaust Gas Recirculation (EGR) System Monitoring The EGR system recirculates a portion of exhaust gas into the intake air stream to reduce nitrogen oxides (NOx) emissions. The EGR valve position is controlled by a DC motor. A position sensor provides feedback on EGR valve control. The following monitors diagnose this system: Exhaust Gas Recirculation Control Circuit - P0403 Detects opens and shorts checks on the EGR control circuit using the ECM electronic output driver circuitry fault detection. Exhaust Gas Recirculation Position Sensor Circuit Low Voltage - P0405 Detects low voltage condition on the position sensor circuit due to a short or open circuit. Exhaust Gas Recirculation Position Sensor Circuit High Voltage - P0406 Detects high voltage condition on the position sensor circuit due to a short-circuit to high voltage. Exhaust Gas Recirculation (EGR) Flow Insufficient - P0401 Detects decreases in EGR flow sufficient enough to cause emission impacts greater than 1.5 X the standard. The intake airflow (MAF) is measured during EGR operations and compared to the expected values. As EGR flow is restricted, MAF values go up beyond what is expected. If failure tolerances are met, the diagnostic code is set. Exhaust Gas Recirculation (EGR) Flow Excessive - P0402 Detects increases in EGR flow sufficient enough to exceed fault tolerances. The intake airflow (MAF) is measured during EGR operations and compared to the expected values. As EGR flow increases beyond desired rates, MAF values go down beyond what is expected. If failure tolerances are met, the diagnostic code is set. Exhaust Gas Recirculation (EGR) Position Sensor Performance - P046C Detects increases and decreases in EGR flow caused by a stuck EGR valve. This diagnosis monitors actual EGR valve position via a position sensor and compares it to desired position. If failure tolerances are met, the diagnostic code is set.
  43. 43. Appendix Appendix-3 E. Engine Controls Component DTC List 1. Fuel Injector Control Circuits a. Fuel Injector Positive Voltage Control Circuits b. Fuel Injector Output Circuits 2. Crankshaft Angle Sensor 3. Camshaft Angle Sensor 4. Manifold Absolute Pressure (MAP) Sensor 5. Barometric Pressure (BARO) Sensor 6. Intake Air Temperature (IAT) Sensor 7. Intake Air Temperature 2 (IMT) Sensor 8. FuelTemperatureSensor 9. EngineCoolantTemperatureSensor 10. Mass Air Flow (MAF) Sensor 11. TurbochargerVanePositionSensor 12. TurbochargerVaneControlSolenoid 13. Glow Plug Control Module and Glow Plugs a. Glow Plug Control Module Internal Circuit b. Glow Plug Circuit c. GPCM-ECMGMLANCommunication 14. Memory(ROM/RAM) 15. Malfunction Indicator Lamp (MIL) Diagnostic 16. Wait To Start (WTS) Lamp Diagnostic 17. ECM-TCMCommunications 18. Vehicle Speed Sensor (VSS) 1. Fuel Injector Control Circuits a. Injector X Control Circuit (P0201 - P0208) The ECM electronic circuit monitors check the injector current during injection events. If errors are detected the respective injector circuit malfunction code (P0201 - P0208) will set. b. Injector Positive Voltage Control Circuit Group X (group 1 thru 4) The ECM electronic circuit monitors, check the four banks of voltage supplies providing power for the injectors. If errors are detected the respective control circuit group malfunction code (P2146, P2149, P2152, P2155) will set. 2. Crankshaft Angle Sensor Crankshaft angle sensor generates fifty-eight (58) pulses per revolution from a special purpose fifty-eight tooth wheel attached to the engine crankshaft. The pulse is used to locate the cylinder reference event (top dead center) for each cylinder. The ECM uses the information to optimize timing, trigger real time events and it is intrinsic to the camshaft angle sensor diagnostic. Circuit Continuity Check Crankshaft Position [CKP] Sensor Circuit - P0335 Detects the circuit continuity of crankshaft angle sensor when the ECM recognizes that the engine is rotating based on the CAM signal.
  44. 44. Appendix Appendix-4 Rationality Check Crankshaft Position [CKP] Sensor Performance - P0336 Detects missing or extra crank pulse by signal analysis and correlating CAM and Crank signals. 3. Camshaft Angle Sensor The CAM position sensor generates 3 pulses per 2 crankshaft revolution. The pulse is used to distinguish whether the cylinder event is compression top dead center or exhaust top dead center at the beginning of engine start. Circuit Continuity Check Camshaft Position [CMP] Sensor Circuit - P0340 Detects the circuit continuity of camshaft angle sensor when the ECM recognizes that the engine is rotating, based on the Crank signal. Rationality Check Camshaft Position (CMP) Sensor Performance - P0341 Detects missing or extra crank pulse by signal analysis and correlating CAM and Crank signals. 4. Manifold Absolute Pressure Sensor The manifold absolute pressure sensor measures the intake manifold pressure, which varies depending on engine speed and load conditions and turbocharger vane position. This pressure is converted to a voltage output, which is monitored by the ECM in order to optimize fuel and timing. The manifold absolute pressure sensor diagnostic consists of two parts; a continuity check, and a rationality check. Circuit Continuity Check The continuity check monitors the manifold absolute pressure signal and determines if the signal has spent a predetermined period of time in an unrealistic region (too high or too low). Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage - P0107 This check is enabled whenever the PCM is powered up. If the measured sensor output is below a calibration voltage for a calibration period of time, the test will fail. Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage - P0108 This check is enabled whenever the PCM is powered up. When the measured sensor output is above a calibration voltage for a calibration period of time, the test will fail. Rationality Check The manifold absolute pressure sensor rationality check verifies the controllability of the manifold pressure under certain engine speed/load conditions. Manifold Absolute Pressure (MAP) Sensor Performance - P0106 Detects a bias sensor by comparing MAP and BARO at engine speeds < a calibration. Both of these pressure sensors exposed to atmospheric pressure should be the same. If they differ by a calibration the code will set. This is also a rationality for the BARO sensor.
  45. 45. Appendix Appendix-5 Turbocharger Over Boost - P0234 This diagnostic checks for an over boost condition when: • The engine is running • Manifold Absolute Pressure sensor code P2564/P2565 is not set. The measured boost is compared to the calibrated diagnostic threshold. If the measured boost is outside the diagnostic parameters a code P0234 is set. Turbocharger Under Boost - P0299 This diagnostic checks for an over boost condition when: • The engine is running • Manifold Absolute Pressure sensor code P2564/P2565 is not set. The measured boost is compared to the calibrated diagnostic threshold. If the measured boost is outside the diagnostic parameters a code P0299 is set. 5. Barometric Pressure Sensor The barometric pressure sensor measures the atmospheric pressure, which varies depending on altitude and weather conditions. This pressure is converted to a voltage output, which is monitored by the ECM in order to optimize fuel and timing. Circuit Continuity Check Barometric Pressure (BARO) Circuit Low Input - P2228 Detects a barometric pressure signal that has spent a predetermined period of time in an unrealistic region (too low). This test runs when the ignition is on. Barometric Pressure (BARO) Circuit High Input - P2229 Detects a barometric pressure signal that has spent a predetermined period of time in an unrealistic region (too high). This test runs when the ignition is on. Rationality Check The rationality check for the BARO sensor is covered by Manifold Absolute Pressure (MAP) Sensor Performance - P0106. (see above) 6. Intake Air Temperature Sensor The intake air temperature sensor is a thermistor type device, located before the turbocharger as part of the MAF assembly. The resistance of the sensor decreases as the intake air gets hot and increases as the intake air gets cold. The sensor resistance and a pull-up resistor form a voltage divider in the ECM. The resulting voltage is measured and converted to a temperature. The control software uses intake air temperature to optimize fuel rate and timing. Circuit Continuity Check Intake Air Temperature Sensor Circuit Low Voltage - P0112 Detects a low voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Intake Air Temperature Sensor Circuit High Voltage - P0113 Detects a high voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set.
  46. 46. Appendix Appendix-6 7. Intake Air Temperature Sensor 2 (IAT2) There is an additional intake air temperature sensor located on the right side of the intake manifold. The IAT 2 sensor functions identically to the IAT 1 sensor. It provides the ECM with the temperature of the actual combustion air as it enters the cylinders. The ECM uses this data in its timing and fuel adjustment calculations to help reduce emissions. Circuit Continuity Check Intake Air Temperature Sensor 2 Circuit Low Voltage - P0097 Detects a low voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Intake Air Temperature Sensor 2 Circuit High Voltage - P0098 Detects a high voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Rationality Check Intake Air Temperature Sensor 1-2 Correlation - P2199 If, at start-up, after a 10 hour engine soak time, the IAT 2 sensor temperature is more than 5.3°C (9°F) higher or lower than the IAT Sensor, the code will set. 8. Fuel Temperature Sensor The fuel temperature sensor is immersed in the diesel fuel returning from the fuel system. The resistance of the sensor decreases as the fuel gets hot and increases as the fuel gets cold. The sensor resistance and a pull-up resistor form a voltage divider in the ECM. The resulting voltage is measured and converted to a temperature. The control software uses fuel temperature to compensate for rail pressure. Circuit Continuity Checks Fuel Temperature Sensor Circuit Low Voltage - P0182 Detects a low voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Fuel Temperature Sensor Circuit High Voltage - P0183 Detects a high voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Rationality Check Fuel Temperature Sensor Performance - P0181 Detects a fuel temperature sensor biased high or low, but still within its normal range. If the engine has been off, as measured by the ignition off timer, for a sufficiently long period of time, this diagnostic compares the fuel temperature soon after engine start with the engine coolant temperature soon after engine start. If the start-up temperature difference between the fuel temperature sensor and the engine coolant temperature (ECT) sensor is within a calibration amount the diagnostic passes. If the start-up temperature difference between the fuel temperature sensor and the engine coolant temperature (ECT) sensor is not within a calibration amount the diagnostic still passes, but block heater influence is tested. Block heater influence is determined by monitoring the IAT during vehicle drive time at speeds greater than a calibration and for a calibrated amount of time. If the IAT drops below a calibrated temperature, block heater influence is suspected and the diagnostic is aborted for this key cycle. If block heater influence has been ruled out and the sensors being compared do not agree, then the diagnostic will set for the second key cycle.
  47. 47. Appendix Appendix-7 9. Engine Coolant Temperature Sensor The engine coolant temperature sensor is a thermistor type device exposed to the engine coolant. The resistance of the sensor decreases as the engine coolant gets hot and increases as the engine coolant gets cold. The sensor resistance and a pull-up resistor form a voltage divider in the ECM. The resulting voltage is measured and converted to the coolant temperature. The control software uses engine coolant temperature in many algorithms i.e. fueling, timing and diagnostics. Circuit Continuity Check Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage - P0117 Detects a low voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Engine Coolant Temperature (ECT) Sensor Circuit High Voltage - P0118 Detects a high voltage on the temperature circuit. If a predetermined period of time in this unrealistic region passes, the code will set. Rationality Check Engine Coolant Temperature (ECT) Sensor Performance - P0116 Detects a fuel temperature sensor biased high or low, but still within its normal range. If at start-up the delta between the engine coolant temperature (ECT) and the intake air temperature (IAT) is less than a calibrated value, the diagnostic will pass. If at start-up the delta between the engine coolant temperature (ECT) and the intake air temperature (IAT) is greater than a calibrated value, block heater influence is tested. Block heater influence is determined by monitoring the IAT during vehicle drive time at speeds greater than a calibration and for a calibrated amount of time. If the IAT drops below a calibrated temperature, block heater influence is suspected and the diagnostic is aborted for this key cycle. If block heater influence has been ruled out, and the sensors compared disagree, the diagnostic will set. 10. Mass Air Flow Sensor The mass airflow sensor measures the mass of the air flowing in the intake manifold. This flow varies depending on the engine speed and load conditions. This airflow is converted to a current output, which is monitored by the ECM in order to optimize fuel and timing. The mass airflow sensor diagnostic consists of two parts, a continuity check and a rationality check. Circuit Continuity Check Mass Air Flow (MAF) Sensor Circuit Low Voltage - P0102 Detects a signal that has spent a predetermined period of time in an unrealistic region (too low). This check is run when the engine speed is within a calibration window. Mass Air Flow (MAF) Sensor Circuit High Voltage - P0103 Detects a signal that has spent a predetermined period of time in an unrealistic region (too high). This check is run all the time. Rationality Check Mass Air Flow (MAF) Sensor Performance - P0101 Detects normalized airflow outside the diagnostic limits. The normalized airflow is derived by dividing the reference (expected) airflow by the actual airflow. This normalized value is compared to the calibration values for the given engineconditions.
  48. 48. Appendix Appendix-8 11. Turbocharger Vane Control Position Sensor The Turbocharger position sensor outputs a voltage corresponding to the turbo vane position. The output voltage is measured and converted to a percent position by the ECM. The vane position will vary to achieve desired boost levels dependent upon engine load and RPM. Circuit Continuity Checks Detects Turbocharger position signals that have spent a predetermined period of time in an unrealistic region. Turbocharger Vane Control Position Sensor Circuit Low Voltage - P2564 Detects sensor output below a calibration voltage. If condition exists for a calibration period of time the code will set. This check is enabled when engine is running. Turbocharger Vane Control Position Sensor Circuit High Voltage - P2565 Detects sensor output above a calibration voltage. If condition exists for a calibration period of time the code will set. This check is enabled when engine is running. Rationality Check Turbocharger Vane Control Position Sensor Performance - P2563 Detects turbocharger vane positions that do not match desired vane positions. The difference between actual vane position and desired position must be within a calibration window. If it is outside of this window for a calibration period of time, the code will set. Turbocharger Vane Control Position Not Learned - P003A Confirms the validity of the position sensor readings when the vanes are being commanded open and then close. If the open value or the close value is outside of their respective window, the code sets. 12. Turbocharger Vane Control Solenoid Circuit This is the turbocharger vane positioning solenoid, which is controlled by modulating its duty cycle. Circuit Continuity Check Turbocharger Vane Control Solenoid Control Circuit - P0045 Detects opens and shorts on the vane positioning solenoid circuit. If during vane positioning the current is out of a realistic range the code sets. 13. Glow Plug Control Module and Glow Plugs a. Glow Plug Control Module Performance - P064C This diagnosis determines if a failure occurred in the glow plug control module. The ECM receives a message from the Glow Plug Control Module confirming the existence of any of the following conditions: supply voltage not connected, glow plug switch is turned off because of overheat, glow plug switch is defective (open or shorted) or voltage sensed by the glow plug control module is too high or too low, ROM/RAM errors exist in GPCM. b. Glow Plug Control Circuit - P0671, P0672, P0673, P0674, P0675, P0676, P0677, P0678 This diagnosis determines if a failure occurred on any of the glow plugs. The ECM receives the message from the Glow Plug Control Module with the status of each glow plug. The status can be: no fault, open or shorted as well as an increase or decrease in resistance detected. If the message received indicates an error for a calibration time, code is set. c. Lost Communications with Glow Plug Control Module - U0106 Detect failures with plug control module system messages sent from the GPCM to the ECM via the GMLAN bus. If any expected messages are not received, then a CAN bus error exists. If the absence of messages is inside the diagnostic's window then a malfunction is indicated.
  49. 49. Appendix Appendix-9 14. Memory (ROM/RAM) The ECM Read Only Memory stores the operational software and calibrations. The memory contents of ROM are maintained even when the ignition is not on and/or the battery terminals are disconnected. The ECM's Random Access Memory maintains software data during ECM operation. The contents of RAM are retained only with the presence of battery connection and ignition on. Control Module Not Programmed - P0602 The intent of this diagnostic is to indicate when a "no-run" calibration is programmed in the ECM. All ECM service parts are delivered with a calibration that allows the module to be secured but does not allow the engine to run. When this particular calibration is installed in the module, this fault code is set to indicate to service technicians that the correct production calibration still needs to be programmed. Control Module Internal Performance - P0606 The intent of this diagnostic is to detect malfunctions within the ECM. Read Only Memory (ROM) is checked by performing a checksum of the contents of all programmed ROM memory parts (operational software and calibrations). This checksum is calculated after every ECM power-up and compared to the imbedded checksums within each software and calibration part. Random Access Memory (RAM) is checked by performing a read and write sequence on every byte of RAM during ECM initialization. If the data being read back is not equivalent to the data that was written, the diagnostic is set. 15. Malfunction Indicator (MIL) Lamp Malfunction Indicator Lamp (MIL) Control Circuit - P0650 Electronic output driver circuitry checks for faults (open/short and no load) on the MIL circuit. The ECM must be commanding the MIL on during a bulb check or DTC activation for the check to run. 16. Wait To Start (WTS) Lamp Wait to Start Lamp (WTS) Control Circuit - P0381 Electronic output driver circuitry checks for faults (open/short and no load) on the WTS circuit. The ECM must be commanding the WTS on during a bulb check or glow plug operation for the check to run. 17. ECM - TCM Communications Lost communications with Transmission Control System - U0101 Detects loss of communication with the TCM resulting from GMLAN buss errors (opens/shorts)
  50. 50. Appendix Appendix-10 18. Vehicle Speed Sensor The vehicle output speed sensor contains a permanent magnet surrounded by a coil that gives off a continuous magnetic field. As the vehicle is driven forward, a speed sensor rotor located near the magnetic pickup of the speed sensor coil also rotates. This rotation produces a variable voltage signal in the pickup coil that is proportional to vehicle speed. On a manual transmission this signal is sent directly to the ECM. On an automatic transmission the speed signal is sent to the Transmission Control Module (TCM), which then sends a replicated version of the signal to the ECM. The ECM uses this information to calculate actual vehicle speed and supply speed information to the cluster and anti-lock brake module. The ECM also uses this information to calculate gear information for manual transmission vehicles. ManualTransmission Vehicle Speed Sensor (VSS) Absence of Signal - P0502 Detects the absence of input signal from the VSS for a calibration amount of time, under conditions of engine torque and speed that would indicate a signal should be present. AutomaticTransmission Diagnosed by the TCM
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  52. 52. June 2005 General Motors Corporation Course#16340.50B PrintedinUSA

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